This invention is related to, although not limited to, the computer-disk drive interface. More specifically, the invention is related to an electronic hardware for the hot swapping of individual disk drives or disk arrays from a microcomputer.
With the rapid development of micro-computers and associated peripherals of higher performance at ever decreasing cost, operating systems with ever increasing functionality and reliability, numerous application software for easy creation of multi-media, content rich information and the explosive advancement of the Internet infrastructure for information delivery and sharing, micro-computer users now routinely demand that their hard disk drives sustain a tremendous data transfer rate while storing voluminous data. For example, one of the latest industry standard definitions of the computer-disk drive Interface, or I/F, is called ATA100, and it specifies a data transfer rate of 100 MB/s (Megabyte/sec) through an 80 wire flat data cable. Additionally, these hard disk drives must be quickly interchangeable with data security followed by easy I/O in the course of data transfer. Since the traditional practice for disk swapping of power cycling and rebooting of the micro-computer is still quite time consuming and prone to system reliability problems, an emerging market requirement for the process of disk swapping is that the micro-computer power supply stay on throughout the process, or the so-called hot swapping of disk drive. With this technique, the hard disk drive can now be easily plugged into and pulled out of the drive rack. In other words, the hard disk drive now behaves more like a removable hard disk.
As the speed of Central Processing Unit (CPU) of the micro-computer continues to increase without bound, the corresponding data transfer rate between a single hard disk drive and the host adapter needs to be improved to maintain the system data throughput. In fact, even at the data transfer rate of 100 MB/s, it is much too slow compared to the speed of CPU and has become the data bottleneck of the computer system. A natural solution for this problem is the deployment of disk arrays working in parallel to ease this data bottleneck. Consequently, the same market requirement of hot swapping also gets applied to the disk array.
Therefore, a solution is needed to allow, with secured access, the hot swapping of individual hard disk drives and disk arrays from a micro-computer while maintaining an ATA100 data transfer rate of 100 MB/s across the computer-disk drive interface, which is an industry standard definition of the computer-disk drive interface.
The first objective of this invention is to devise a technique that allows the hot swapping of individual hard disk drives and disk arrays from a micro-computer, thus effectively making the hard disk drive or disk array behave more like a removable hard disk or removable disk array.
The second objective of this invention is to devise a technique that allows the hot swapping of individual hard disk drives and disk arrays from a micro-computer wherein the computer-disk drive interface is the industry standard ATA100.
The third objective of this invention is to devise a technique that allows the hot swapping of individual hard disk drives and disk arrays from a microcomputer with secured access.
Other objectives, together with the foregoing are attained in the exercise of the invention pursuant to the following description and resulting in the embodiment illustrated in the accompanying drawings.